Turkey and Russia have agreed on the technical details of a contract that would supply Ankara with the S-400 Triumf long-range anti-aircraft missile system, Victor Kladov, the director for international cooperation and regional policy for Russian state conglomerate Rostec, said last week.

Turkey's ministry of defence has neither declined nor confirmed Kladov's statement. Numan Kurtulmus, Turkey's deputy prime minister said on Monday that two sides had not signed the contract yet, but the prior conditions were about to be finalised.

No other NATO country has bought the advanced air defence systems before.

The news about the deal raised questions as to why Turkey, which is a NATO member and hosts a base for the military alliance, decided to acquire Russian missiles that are believed to be incompatible with the systems used by NATO.

According to the report, the two countries agreed on a two-battery system with 240 warheads, and search-detection-tracking and baffle radars for $2.5bn.

That sum will be split by Ankara and Moscow, and Turkey will receive the system within two and a half years.

Turkey and Russia have agreed on the technical details of a contract that would supply Ankara with the S-400 Triumf long-range anti-aircraft missile system, Victor Kladov, the director for international cooperation and regional policy for Russian state conglomerate Rostec, said last week.

Turkey's ministry of defence has neither declined nor confirmed Kladov's statement. Numan Kurtulmus, Turkey's deputy prime minister said on Monday that two sides had not signed the contract yet, but the prior conditions were about to be finalised.

No other NATO country has bought the advanced air defence systems before.

The news about the deal raised questions as to why Turkey, which is a NATO member and hosts a base for the military alliance, decided to acquire Russian missiles that are believed to be incompatible with the systems used by NATO.

According to the report, the two countries agreed on a two-battery system with 240 warheads, and search-detection-tracking and baffle radars for $2.5bn.

That sum will be split by Ankara and Moscow, and Turkey will receive the system within two and a half years.